#!/usr/bin/env python
# coding=utf-8
"""
此模块还需优化
"""
import random
from PIL import Image, ImageDraw, ImageFont, ImageFilter

_letter_cases = "abcdefghjkmnpqrstuvwxy"  # 小写字母，去除可能干扰的i，l，o，z
_upper_cases = _letter_cases.upper()  # 大写字母
_numbers = ''.join(map(str, range(3, 10)))  # 数字
init_chars = ''.join((_letter_cases, _upper_cases, _numbers))


def create_validate_code(
        size=(100, 30),
        chars=init_chars,
        img_type="GIF",
        mode="RGB",
        bg_color=(255, 255, 255),
        fg_color=(0, 0, 255),
        font_size=18,
        font_type="forum/wqy.ttc",
        length=4,
        draw_lines=True,
        n_line=(1, 2),
        draw_points=True,
        point_chance=2):
    '''
        @todo: 生成验证码图片
        @param size: 图片的大小，格式（宽，高），默认为(120, 30)
        @param chars: 允许的字符集合，格式字符串
        @param img_type: 图片保存的格式，默认为GIF，可选的为GIF，JPEG，TIFF，PNG
        @param mode: 图片模式，默认为RGB
        @param bg_color: 背景颜色，默认为白色
        @param fg_color: 前景色，验证码字符颜色，默认为蓝色#0000FF
        @param font_size: 验证码字体大小
        @param font_type: 验证码字体，默认为 ae_AlArabiya.ttf
        @param length: 验证码字符个数
        @param draw_lines: 是否划干扰线
        @param n_lines: 干扰线的条数范围，格式元组，默认为(1, 2)，只有draw_lines为True时有效
        @param draw_points: 是否画干扰点
        @param point_chance: 干扰点出现的概率，大小范围[0, 100]
        @return: [0]: PIL Image实例
        @return: [1]: 验证码图片中的字符串
    '''

    width, height = size  # 宽， 高
    img = Image.new(mode, size, bg_color)  # 创建图形
    draw = ImageDraw.Draw(img)  # 创建画笔

    def get_chars():
        '''生成给定长度的字符串，返回列表格式'''
        return random.sample(chars, length)

    def create_lines():
        '''绘制干扰线'''
        line_num = random.randint(*n_line)  # 干扰线条数

        for i in range(line_num):
            # 起始点
            begin = (random.randint(0, size[0]), random.randint(0, size[1]))
            # 结束点
            end = (random.randint(0, size[0]), random.randint(0, size[1]))
            draw.line([begin, end], fill=(0, 0, 0))

    def create_points():
        '''绘制干扰点'''
        chance = min(100, max(0, int(point_chance)))  # 大小限制在[0, 100]

        for w in range(width):
            for h in range(height):
                tmp = random.randint(0, 100)
                if tmp > 100 - chance:
                    draw.point((w, h), fill=(0, 0, 0))

    def create_strs():
        '''绘制验证码字符'''
        c_chars = get_chars()
        strs = ' %s ' % ' '.join(c_chars)  # 每个字符前后以空格隔开

        font = ImageFont.truetype(font_type, font_size)
        font_width, font_height = font.getsize(strs)

        draw.text(((width - font_width) / 3, (height - font_height) / 3),
                  strs,
                  font=font,
                  fill=fg_color)

        return ''.join(c_chars)

    if draw_lines:
        create_lines()
    if draw_points:
        create_points()
    strs = create_strs()

    # 图形扭曲参数
    params = [
        1 - float(random.randint(1, 2)) / 100, 0, 0, 0,
        1 - float(random.randint(1, 10)) / 100,
        float(random.randint(1, 2)) / 500, 0.001,
        float(random.randint(1, 2)) / 500
    ]
    img = img.transform(size, Image.PERSPECTIVE, params)  # 创建扭曲

    img = img.filter(ImageFilter.EDGE_ENHANCE_MORE)  # 滤镜，边界加强（阈值更大）

    return img, strs


if __name__ == "__main__":
    mstream = StringIO.StringIO()
    code_img = create_validate_code()[0]
    code_img.save("validate.gif", "GIF")
    # code_imgimg.save(mstream, "GIF")
    # request.session['validate'] = validate_code[1]
    # return HttpResponse(mstream.getvalue(), "image/gif")
